ARMY TM 5-5420-212-10-1
MARINE CORPS TM 08676A-10/1-1
3-17
DOUBLE STORY 2E+13 thru 2E+22 BAY DESIGN WITH LRS
The procedures that follow are for design of DS 2E + 13 through 2E + 22 bay MGBs (w/LRS) on normal sites
where water level or any obstructions are at least 3.7 m below bank heights:
a.
Measure the AR gap (para. 3-10a)
b.
Select a bridge (para. 3-10b and Table 3-31)
Table 3-31. DS MGB Design13-22 Bays with LRS
Site and Bridge Dimensions
AR GAP
RANGES
(a)
MLC*
(b)
2E + No. of
Bays
(c)
Bridge
Length L
(d)
R Distance
(e)
Nose Const
(f)
28.3-30.9
70(T)
13
32.9
27.7
7N1
30.2-32.8
70(T)
14
34.8
29.0
7N1
32.0-34.1
70(T)
15
36.6
29.0
7N1
33.8-36.4
70(T)
16
38.4
29.6
8N1
35.6-38.2
70(T)
17
40.2
29.6
8N1
37.5-40.1
70(T)
18
42.1
29.6
6N1+3N2
39.3-41.9
70(T)
19
43.9
35.1
6N1+3N2
41.1-43.7
70(T)
20
45.7
38.7
6N1+3N2
43.0-45.1
70(T)
21
47.6
38.7
6N1+3N2
44.8-46.2
70(T)
22
49.4
40.5
6N1+3N2
* See step k. Slope Check and Table 1-1 for crossing restrictions and MLC 100(W) capability. (T) = Tracked
c.
Bridge Length
Read and note the number of bays and bridge length, Table 3-31 columns (c) and (d).
d.
R Distance
Read and note the R distance, Table 3-31 column (e).
e.
Nose Construction
Read and note the nose configuration, Table 3-31 column (f).
f.
Key Construction Points
Identify, locate and take elevations at the key construction points. These construction points are explained below and
shown in Figure 3-15.
(1)
F peg-Designates the location of the far bank end of bridge (outer edge of bankseat beam). Initially
placed distance given as minimum bearing in Table 3-32 for the bridge being designed. The distance, between the A and
F peg is the amount of bridge that will bear on the far bank, and is known as the far bank bearing.
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